FIG. 1 is a schematic view of a known technique. Taking a filter mounting structure of an conventional heat exchange device as an example, as shown in FIG. 1, a casing 3 of the heat exchange device 1 comprises of an upper, a lower, a front, a back, a left and a right side panels. The heat exchange device 1 may be mounted on the wall directly. A filter 2 is placed in a filter placing frame 5, and a mounting opening 6 for the filter placing frame 5 and a cover 7 which is fixed on the mounting opening 6 with screws are formed in the front side panel 4 of the casing 3. The filter placing frame 5 and the cover 7 can be fixed together. When the filter 2 needs to be washed or changed, the screws are removed firstly, and then the cover 7 and the filter placing frame 5 can be taken out through the mounting opening 6.
When an obstacle such as an interior furniture, is placed in the way ahead of the cover 7, it is necessary to move away the obstacle and then perform an operation. It is also possible to remove a side panel from one side of the casing and then take out the filter placing frame 5. However, no matter which method is used, there are too many steps and the operation is inconvenient.